Materials Literature
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A range of monodomain nematic liquid crystal elastomers containing differing proportions of photo-isomerisable mesogenic moieties, which turn from a rod-like to a kinked shape upon ultraviolet (UV) irradiation, was studied. Depending on the proportion and positional role of the photo-sensitive groups in the crosslinke…
We studied the mechanical properties of dragline threads of the edible golden silk spider Nephila edulis that are produced under spinning speeds ranging from 0.1 to 400 mm s(-1) and temperatures ranging from 5 to 40 degrees C. These conditions affected the silk in all of the mechanical traits we tested (strain at brea…
Single-wall carbon nanotubes pack into crystalline ropes that aggregate into tangled networks due to strong van der Waals attraction. Aggregation acts as an obstacle to most applications, and diminishes the special properties of the individual tubes. We describe a simple procedure for dispersing as-produced nanotubes…
A variety of spectroscopy and sample preparation techniques are described that allow chemical composition changes to be followed for isolated clearcoat samples, clearcoats in complete paint systems, and all coating layers in complete paint systems as a function of exposure. The analysis techniques provide photooxidati…
Abstract Polyurethane dispersions were prepared and urethane/acrylic composite latices were synthesized with polyurethane dispersions as the seed, and core‐shell emulsion polymerization. Fourier‐transform infrared spectroscopy coupled with attenuated total reflectance (FTIR‐ATR) analyses showed that the films obtained…
Abstract The synthesis and characterization of a new series of chiral poly(ester‐amide)s are reported. They were prepared by the simple reaction of diacid chlorides with biphenolic azo chromophores and optically active dihydroxy compound (isosorbide) in dimethyl acetamide at 100 °C. The polymers containing isosorbide…
I. Introduction In this paper, we will consider, first, the fundamentals of the measurement of corrosion protection of organic coatings. This first portion will emphasize electrochemical characterization methods for the corrosion protective properties of organic coatings, especially electrochemical methods, and the in…
A straightforward procedure for engineering porosity in thin silicate films has been demonstrated. Macroporous silicate films were fabricated by doping a silica sol prepared from the acid-catalyzed condensation of tetramethoxysilane with polystyrene latex spheres of diameter ranging from 0.3 to 1 μm. After film format…
Abstract The solution properties of hydroxyl terminated hyperbranched aliphatic polyesters and their acetyl derivatives have been studied by measuring viscosity parameters. The polarity of terminated groups of molecules is the most important factor affecting their properties. The intrinsic viscosity [η] cannot reflect…
The recently developed technique of maximum-likelihood density modification [Terwilliger (2000), Acta Cryst. D56, 965-972] allows a calculation of phase probabilities based on the likelihood of the electron-density map to be carried out separately from the calculation of any prior phase probabilities. Here, it is show…
Abstract A series of low‐density polyethylene (LDPE) blends with varying proportions of plasticized tapioca starch have been used for the study of their mechanical properties. A functionalized epoxy resin, namely, poly(ethylene‐ co ‐glycidyl methacrylate) has been used as the compatibilizer. The impact and tensile pro…
The binding of N-acetylglucosamine (NAG) to chicken egg lysozyme (E.C. 3.2.1.17) was investigated by high-resolution X-ray powder diffraction at room temperature. NAG was found to bind to lysozyme in a rapid precipitation preparation with 0.05 M NaCl buffer pH 6.0, but not 0.05 M NaCl buffer pH 5.0. Binding was indica…
Nonlinear behaviour of power piezoceramic materials has to be studied under strong electric fields. A bridge designed for measuring it at low frequency is described. It consists basically of a capacitance comparison bridge that can be used in two different modes: balanced and unbalanced. The nonlinear electric displac…
Colloidal suspensions of clay particles in aqueous salt solutions make ideal model systems for the study of interactions between plate-shaped particles, due to the ease in tuning their electrostatic repulsion with the concentration of the salt. Numerous gel and sol structures are possible, including nematic liquid cry…
We achieved enhancement of colossal magnetoresistance at room temperature in a tensile strained ${\mathrm{La}}_{0.8}{\mathrm{Ba}}_{0.2}{\mathrm{MnO}}_{3}$ thin film (52% at 297 K under an applied field of 0.8 T). Surprisingly, the tensile strain increased the Curie temperature ${T}_{C}$ from 270 K in the bulk to 320 K…
The weak signal obtained from the anomalous scattering (at lambda = 1.54 A) of naturally occurring elements such as sulfur, phosphorus and ordered solvent chloride ions is used to determine the atomic positions of these atoms. Two examples are discussed: the sulfur and chlorine substructure of tetragonal hen egg-white…
Abstract The present work focuses on the compatibization of styrene‐ co ‐butadiene rubber (SBR)/acrylonitrile‐ co ‐butadiene rubber (NBR) blends with dichlorocarbene modified styrene‐ co ‐butadiene rubber (DCSBR) as a function of concentration of compatibilizer and composition of the blend. FTIR studies, differential…
By a direct combination of the fast initiation technique and a selective quantitative termination reaction, terminally functionalized poly( N -propionylethylenimine)s (PPEIs) were prepared by cationic living ring-opening polymerization of 2-ethyl-2-oxazoline in a one-pot multistep reaction. The chain ends of the linea…
We investigated the influence of catalyst preparation on the growth of coil-shaped nanotubes by varying the pH of the solution during catalyst impregnation, to elucidate their formation process. The spirals were observed by transmission electron microscopy, and we determined the dimensions of these coils for a large n…
Trends in the stability of alpha- and beta-Keggin heteropolytungstates of the second-row main-group heteroatoms Al(III), Si(IV), and P(V) are elaborated by data that establish the roles of kinetic and thermodynamic control in the formation and isomerization of Keggin tungstoaluminates. Slow, room-temperature co-conden…